J&B Aviation’s patented Thermgard® thermal sensor is strategically placed in the contact section to constantly monitor the temperature of the ground power connector at the aircraft. When the temperature reaches a predetermined setting, the sensor causes 400Hz power to disconnect from the aircraft. The Thermgard® replacement contact section is used on the same cables as JB7174, JB5101, JB5103 and JB5104 series of Field Replacement connectors.